• Knowledge Management Research
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• v.14 no.1
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• pp.73-94
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• 2013

Customer's purchase state consists of purchase inertia and variety-seeking. As the growing brand familiarity triggers the increase of brand attractiveness, customers purchase state will be of inertia. However the excessively growing brand familiarity ignites the decrease of brand attractiveness. Followingly the purchase state will be tend to plunge into the variety-seeking state. The main topic of this study is to validate the asymmetric formation of customer's purchase states between inertia and variety-seeking. In order to follow up the main topic, this article introduces a model to freely describe the velocity of value changes depending upon the purchase states. This model will help overcome the limitation of the past studies having been based on the symmetric value changes. Based on this approach marketer will be able to decide the timing of sales promotions. This research utilized local telecommunication carrier's database of smartphone application purchase/download records. This database was collected from two years (2009 and 2010) span, the time when the smartphones started commodifying in Korea whilst most of the past studies had used purchase data of maturity stage products. From this approach utilizing the introduction stage data in the product life cycle, the probability of brand choice depending upon the purchase state on the early-stage can be probed. Moreover, this study tries to expand the research methodology from the other areas of research by knowledge sharing. Here this study introduces the methodology of section-aggregated multinomial logit to simultaneously estimate the parameters that were included in the plural multinomial logit functions while the plural functions were inter-connected. This adoption of section-aggregated multinomial logit model procedures from the computerized statistics areas is expected to nourish the marketing research for more precise analysis and estimation of effects of marketing activities.

• Environmental and Resource Economics Review
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• v.16 no.4
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• pp.873-900
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• 2007

Non-market valuation studies tend to assume that individual households have homogeneous preferences for a non-market good to value. However, since the preferences for non-market goods, especially environmental goods are more likely to be heterogeneous by nature, it may be more appropriate to assume heterogeneous preferences for non-market goods, which may in turn may lead to reduced biases in the WTP estimation. This study investigate the extent to which individual households have heterogeneous preferences for reduced concentrations of radon, a radioactive indoor air pollutant, for road safety, and for nuclear power safety. We also analyze the effect of heterogeneity assumption on the results of model and WTP estimation. Using the choice experiments and mixed logit models, we found that allowing for heterogeneous preferences improved model fitness and that there existed heterogeneous preferences for both reduced radon concentration and road safety, albeit not for nuclear power safety. The mean WTP for reduced radon concentrations and road safety increased by factors of 2.44 and l.74 respectively with the models allowing for heterogeneous preferences.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.288-298
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• 2017

The system of high-speed and conventional railway vehicles is diversified, and significant technological development in performance has been achieved. This study analyzed the modal change characteristics; furthermore, it estimated the value of travel time by improving the travel time and cost for the passenger's perception of railway. In this study, we formulate a mode choice model for passengers and compare it with the mixed logit model which reflects individual taste variation. In addition, the validity of the analysis is presented through an estimation the value of travel time using the derived model. For this purpose, a stated preference survey was conducted with 510 people using public transportation. The benefits of time-saving can be accurately determined by estimating the value of time spent on the railway. Appropriate fares for public transportation can also be estimated.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.620-635
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• 2017

This study was intended to identify the main factors responsible for the decline in purchase of imported agricultural and fish products after Japan's nuclear power plant accident in 2011 and to compare the effects on imported agricultural produce and imported fish products. Logit model and multiple regression model analyses were performed using consumers' survey data. Psychological and qualitative factors reflecting consumers' food safety awareness and purchasing preferences, which were extracted by Factor analysis, were included as the models' explanatory variables, along with socio-demographic and economic factors. The Logit estimation showed aged, married, and low-income households had significantly higher probability of reducing their purchases of imported agricultural and fish products. However, the multiple regression results pointed out that the actual rate of decrease of imported agricultural and fish products purchases were more significantly affected by non-socio demographic factors such as past experience of purchasing imported agricultural and fish products, future intention to purchasing Japanese agricultural and fish products, and the ratio of imported to domestic agricultural and fish products before the nuclear accident, as well as consumers' feeling of food insecurity and their purchasing preferences. Moreover, the results showed that Korean consumers have reacted more sensitively to the decline in imported fish products than imported agricultural produce after the nuclear accident based on the marginal effects of various socio-demographic and economic factors.

• Journal of Labour Economics
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• v.41 no.3
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• pp.95-128
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• 2018

This study tries to measure the change in the state dependence of the three labor supply choices (part-time, full-time, and the state of unemployed) in Korean married women's labor market by estimating the dynamic multinomial logit model based on MSL (maximum simulated likelihood) method. A component representing individual's unobserved characteristics has been introduced, because it is crucial to control for unobserved heterogeneity in assessing the state dependence. Estimation results show that the state dependences of the three alternatives have strengthened recently. Therefore, part-time job has become more likely to be functioning as an extra option to participate in labor market rather than a bridge(stepping stone) or shelter between unemployment and full-time job.

• Environmental and Resource Economics Review
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• v.13 no.4
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• pp.685-715
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• 2004

This study applies two-choice model to identify the major determinants of NIMBY attitudes when a large-scale composting facility is built around a residential area. Using a survey data of residents in Jeju City, Korea, logit estimation is implemented. The empirical results are consistent with the implication of the specified model: a representative resident's NIMBY attitude is positively (negatively) affected by "Negative Neighborhood Characteristic Variables" ("Positive Wealth Attribute variables"). Socio-demographic variables may be summarized as mostly statistically insignificant, which implies that policy makers may have to take into consideration their region-specific socio-demographic factors instead of simply emulating the policies which have been successful elsewhere.

• The Journal of Information Systems
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• v.27 no.4
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• pp.149-165
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• 2018

Purpose As Korean economy has been sluggish in recent years, firms' interest in publicly financed projects has increased due to the relatively increasing proportion in the economy. Since 1999, publicly financed projects in Korea need to undergo preliminary feasibility study to evaluate economic efficiency and policy quality if they are larger than a certain scale. The benefits of public projects are one of the most important factors in the preliminary feasibility study but are difficult to estimate due to their nature. Design/methodology/approach This study estimates the benefits of the agricultural soil information database, a public database in Korea. The method used in the study is the stated preference method which is formally used in Korea's preliminary feasibility study. Data are collected through surveys and a logit model is constructed to be estimated by the maximum likelihood estimation method. Findings As the first study evaluating a public database, this study can be used as a baseline in all public database projects developed in the future. In addition, this study can contribute to improving the understanding of both private companies and public organizations who are interested in the cost-benefit analysis and estimation procedure for the publicly financed projects.

• Journal of the Korean Data and Information Science Society
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• v.19 no.2
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• pp.559-568
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• 2008

This paper analyzes Korean residential tenure choice for house which is the most important in Korean households' assets. Data used in the analysis is the data of Korean Labor and Income Panel Study for the period from 1998 to 2006 and with 2341 households. In this paper, a household chooses a housing tenure mode, either by renting or by owing house. We use a mixed-logit panel model as an estimation model to take into consideration household's heteroscedasticity of preference in tenure choice. It turns out that the heteroscedasticity is significant in households' tenure choice behavior, implying that Korean housing policy emphasizing supply side should consider the demand side.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.2
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• pp.87-93
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• 2010

The partial least squares (PLS) method is popularly used for estimating the structural equation model, but the existing algorithm may not be directly implemented when probabilities are involved in some constructs or manifest variables. We propose a structural equation model including the brand choice as one construct having brand choice probabilities as its manifest variables. Then, we develop a PLS-based algorithm for the structural equation model by utilizing the multinomial logit model. A case is introduced as an application and simulation studies are performed to validate the proposed algorithm.

• Journal of Korean Academy of Nursing
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• v.43 no.2
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• pp.154-164
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• 2013

Purpose: The purpose of this article is twofold: 1) introducing logistic regression (LR), a multivariable method for modeling the relationship between multiple independent variables and a categorical dependent variable, and 2) examining use and reporting of LR in the nursing literature. Methods: Text books on LR and research articles employing LR as main statistical analysis were reviewed. Twenty-three articles published between 2010 and 2011 in the Journal of Korean Academy of Nursing were analyzed for proper use and reporting of LR models. Results: Logistic regression from basic concepts such as odds, odds ratio, logit transformation and logistic curve, assumption, fitting, reporting and interpreting to cautions were presented. Substantial shortcomings were found in both use of LR and reporting of results. For many studies, sample size was not sufficiently large to call into question the accuracy of the regression model. Additionally, only one study reported validation analysis. Conclusion: Nursing researchers need to pay greater attention to guidelines concerning the use and reporting of LR models.